Colorblindness strikes between 5 and 10 percent of males and about 0.1 percent of women.

Dr. Gregory Batts, an optometrist at Paducah’s Keene Optical, said humans enjoy color vision thanks to specialized photo receptors on the retina. Each specializes in interpreting red, green, blue or yellow. A defect in these receptors may keep a person from perceiving one or all of the colors.

Batts said colorblindness is linked to the X chromosome. A man has only one X chromosome, so if he has this trait, he is likely to be colorblind. Women have two X chromosomes, so if one has the trait, they will have full color vision, but carry that trait. If a woman has it linked to both X chromosomes, they would be colorblind.

“There are so many levels of severity of colorblindness,” Batts said. “Some might see a nice vivid red and not be able to differentiate it from that ugly Tennessee orange. Some have a condition called achromatopsia and see every color as a shade of gray.”

Batts said colorblindness is not debilitating to most people. Drivers still recognize the octagonal shape of stop signs and know the order of lights on a signal.

“It could be a problem for an electrician to recognize the color-coding of wires, or maybe a fashion designer, or might keep a cook from knowing if the meat was still red or pink, but most people adapt well,” Batts said.

Batts said colorblindness does not have a medical or surgical cure. Optometrists and ophthalmologists may fit a colorblind patient with a single red contact to better perceive changes in the red spectrum. He said this is sometimes done with electricians, but not common. While a red lens in glasses is also an option, he has never made a pair of glasses with one red lens due to the obvious unusual appearance.

Celeste Emerson, district health coordinator for Paducah Public Schools, said she has seen few referrals for colorblindness. The district does not routinely screen for the condition, but will refer students and parents for an eye exam when it is suspected. Stigma is avoided by teachers adjusting plans to accomodate a student’s colorblindness, such as avoiding organization by color-coding.

“If there is a problem, we would have our teachers work more closely with the student and help them distinguish what they need to know or if they are having difficulties, plan for their needs,” Emerson said.

If a parent or teacher suspects colorblindness or another visual impairment, Emerson recommends a consultation with an optometrist or ophthalmologist. If a parent is uninsured or under-insured, the school resource office may be able to provide a referral for visual screenings at a reduced cost.